Convertible horn radiator-coupler for separable missile



Jan. 3, 1967 E. N. RODDA 3,296,620

CONVERTIBLE HORN RADIATOR-GOUPLER FOR SEPARABLE MISSILE Filed NOV. 20, 1963 v I I) IIAHMI'! IE-g 2 a m g INVENTOR.

ELLSWORTH N. RODDA ATTORNEY I United States Patent CONVERTIBLE HORN RADIATOR-COUPLER FOR SEPARABLE MISSILE Ellsworth N. Rodda, San Jose, Calif., assignor, by mesne assignments, to the United States of America as rep-- resented by the Secretary of the Navy Filed Nov. 20, 1963, Ser. No. 325,188 8 Claims. (Cl. 343-705) The present invention relates in general to the transmission of micro-wave energy, and, in particular, relates to means for coupling RF energy between two separable portions of an airborne vehicle, such as a multi-stage missile, while at the same time providing for the transmission of data through the atmosphere from such missile to a remote receiving point after the two portions of the vehicle have separated.

It is frequently desirable to couple RF energy between two separable devices which, when together, comprise a unitary structure. One. example of such an apparatus consists of a missile or rocket having a plurality of stages which sequentially separate as the missile travels through the earths atmosphere. During the initial period or periods of flight, it is often required that RF energy be transferred from one portion of the assembly to another with-out appreciable loss. However, after certain stages of the missile are no longer active, it is desirable that the RF energy which was previously coupled thereinto now be radiated into space for reception at some remote point such as a ground station or tracking aircraft.

Difficulty has heretofore been experienced in achieving both of these objectives without excessively complicating the missile structure and/ or materially adding to its overall size and weight. Even when such requirements were partially met, the radiation which was emitted into space was not sufficiently directive, and a considerable amount of power was dissipated in a lateral direction, or, in other words, transverse to the longitudinal axis of the missile. Consequently, either additional energy had to be generated to overcome this power loss, or else the range over which reception was possible was severely limited.

It is a feature of the present invention to provide an apparatus which will overcome the above difficulties. In accordance with a preferred embodiment thereof, a coupling device is disclosed which will act to transfer highfrequency energy from one portion of a separable body to another portion thereof with a minimum of loss, this device being so designed that one section thereof is formed integrally with one portion of the separable body, while the other section of the device is formed integrally with the remaining portion. The coupling device is so fabricated as to separate under pressure in approximately the same plane as that which effectively divides the two portions of the separable body. In effect, therefore, following separation of the two portions of the body, one section of the coupling device will remain with each body portion. In the case of a multi-stage missile, energy can be coupled from the head into a succeeding stage during the initial phase of missile flight, while, after separation of such succeeding stage, the remaining section of the coupling device acts as an antenna to radiate energy into the atmosphere or into space, as the case may be. It will thus be seen that the coupling device of the present disclosure performs two distinct functions successively, and without the inclusion of any components in addition to those initially utilized. The preferred embodiment of the invention described herein incorporates a radiating element in the form of a helix surrounded by a conical reflector of the horn type. When the invention structure is employed on a mnlti-stage missile, for example, this radiating element forms part of, and remains with, the forward stage or warhead. The remaining portion of the coupling device (with which the antenna unit is associated) is built into the immediately following missile stage, and is designed to fall away from the for- Ward stage at some point during missile fiight.

One object of the present invention, therefore, is to provide a combined microwave coupling device and antenna particularly designed for use with a multi-stage airborne vehicle so arranged as to separate into at least two portions during its operational cycle.

A further object of the invention is to provide a combined coupling device and antenna acting to transfer RF energy between two portions of a separable multi-stage apparatus with a minimum of loss prior to separation, and further acting to radiate such energy in a predetermined direction following separation, such radiation being unimpeded by any structure by which the antenna is surrounded.

Other objects, advantages, and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings wherein:

FIG. 1 is a longitudinal cross-sectional view of a pre ferred embodiment of the present invention while in its assembled condition; and

FIG. 2 is a reduced exterior view of the device of FIG. 1 following separation of the two portions thereof.

Referring now to FIG. 1 of the drawings, there is shown a combined RF coupling unit and antenna particularly designed for employment in a multi-stage assembly at least two portions of which are intended to sepa rate during operation. The device of FIG. 1 functions as an inter-stage coupler acting to transfer high-frequency energy between two sections of the assembly prior to their separation, and to further function as a transmitting antenna radiating energy into space after such separation has occurred.

To carry out the above function, the device of FIG. 1 is made up of two portions which are intended to be respectively associated with two portions of a separable body, such, for example, as a multi-stage missile (not shown). One such portion of the device includes both an antenna section, generally identified by the reference numeral 10, and an impedance-matching transformer or adaptor, generally identified by the reference numeral 12. These two units are intended to be mounted on, or incorporated in, one portion of the separable body. The remaining section of the invention device includes a furthur impedance-matching transformer or adaptor generally identified by the reference numeral 14. The latter section includes means for frangibly securing such section to the antenna assembly 10, and the construction and operation of such means will be described below. At this point however, it-should be noted that the two sections 10 and 12 are carried by one portion of the separable body, while the section 14 is carried by a further portion thereof. The device illustrated in FIG. 1 is designed to break away along a line 16 when the two portions of the body on which the device of FIG. 1 is mounted separate from one another.

The device of FIG. 1 is intended to transfer high-frequency energy from one portion of a separable body to another portion thereof, each such body portion including a coaxial transmission line (not shown) the respective inner conductors of which are receivable in a pair of pronged connectors 18 and 20 which form part of the respective impedance-matching transformers 12 and 14. As illustrated in the drawing, the connector 18 constitutes the outer termination of the center conductor 22 of transformer 12, the opposite end of which conductor is provided with a further pronged connector 24. Surrounding the center conductor 22 is a mass of dielectric material 26 which fills a cavity formed by the essentially tubular enclosure or housing 28 of the transformer. As also shown in FIG. 1, the tubular transformer housing 28 is provided with a flanged extension 30 which extends in a radial direction. An annular metallic iris 32 is receivable in a recess in the flange 30, and serves to partially enclose the dielectric material 26 within the transformer cavity and provide electrical tuning to the transition area. The outermost terminal portion of the housing 28 is threaded so that electrical engagement may be made with the outer conductor of the coaxial line (not shown) to the inner conductor of which the pronged connector 18 is associated. In order to achieve a proper impedance matching between the device of FIG. 1 and the two coaxial lines to which the transformers 12 and 14 are respectively connected, the latter are provided with tuning screw 34 and 36 which are radially adjustable in order to vary the gap between each such screw and the center conductor of its transformer.

At the opposite end of the assembly of FIG. 1 is the second impedance-matching transformer 14. This transformer 14 corresponds in all respects to transformer 12 just described, and is intended to be connected to a further coaxial transmission line the inner conductor of which is receivable in the pronged connector 20.

As shown in the drawing, the two transformers 12 and 14 are positioned so as to lie in spaced-apart face-to-face relationship. Interposed therebetween is the antenna unit which has been previously referred to and designated by the reference numeral 19. This antenna unit is designed to be integral with the transformer 12, and includes an axially-mounted tubular support 38 composed of electrically insulating material and having a radially-extending flange 40 at the end thereof proximate to the iris 32. The latter thus lies in direct contact with the flange 40 throughout a major portion of its radial dimension.

As further shown in the drawing, the pronged connector 24 of transformer 12 extends through an axial opening in the iris 32, and receives therewithin one end of a helicallywound conductor 42 which, as will later be brought out, serves as an antenna following separation of the transformer 14 from the remainder of the assembly. This conductor 42 overlies the outer surface of the tubular support 38, and extends to the vicinity of transformer 14, where its remaining end is receivable in a pronged connector 44 which corresponds the connector 24 of transformer 12. It should be emphasized, however, that the pronged connector 44, while entering into good electrical engagement with the conductor 42, nevertheless allows the latter to emerge therefrom when a separating force is developed between the antenna section of FIG. 1 and the transformer unit 14 in a manner to be subsequently described.

In addition to the helically wound conductor 42, the antenna section 10 of the device of FIG. 1 includes a horn reflector 46 which serves to direct the electromagnetic energy developed by the helix 42 in an axial direction when the two sections of the assembly have separated. This re flector 46 is essentially frusto-conical in configuration, and is provided with a flanged portion 48 designed to lie in face-to-face relationship with the flanged portion 30 of the transformer 12. A plurality of aligned apertures 50 are formed in the two flanges 30 and 48 to respectively receive a plurality of bolts 52 which secure together in unitary fashion the antenna section 10 and the transformer 12. As illustrated, the flange 48 is further formed with an axial aperture 54 through which projects the cylindrical support 38 on which the helical conductor 42 is wound.

In order to maintain the antenna section 10 of the device in the position shown in the drawing with respect to the transformer section 14 during the time that the separable portions of the apparatus on which the coupling device is carried are in their assembled condition, the cylindrical housing 56 is provided with a radially-flanged extension 58 which is similar in all respects to the flanged extension 30 formed on the cylindrical housing 28 of trans-' former 12. To adapt the transformer section 14 to the antenna section 10 in separable fashion, there is provided an iris 60 which is of generally annular configuration, and has an outer diameter identical to that of the flange 58. However, this iris 60 has a portion of its outer periphery recessed at 62 so that the outer diameter of this recessed portion corresponds to the inner diameter of the horn reflector 46 at the outer extremity of the reflector. This enables a force fit to be brought about between the iris 60 and the reflector 46, the engagement between these members, however, being capable of termination when the transformer section 14 separates from the antenna section 19 along the line 16.

The iris 60 is designed with an axial opening 64 through which the helix 42 projects in order to enter into separable electrical engagement with the inner pronged connector 44 which terminates the inner conductor 68 of the transformer unit 14. In addition, the iris 60 is provided with a plurality of openings aligned with corresponding openings in the flange 5S, and through which a plurality of bolts 70 act to secure the iris in face-to-face relationship with theflange 58.

When the two portions of the airborne vehicle upon which the apparatus of FIG. 1 separate, the antenna section 10 becomes disengaged from the transformer section 14 along the line indicated in FIG. 1 by the reference numeral 16. In other words, the apparatus of the drawing divides in the manner illustrated in FIG. 2. It will now be appreciated that, with the transformer section 14 (including the iris 60) no longer present to close the wide end of horn 46, the helical conductor 42 will act as a radiating element to emit into space electromagnetic energy arriving at the assembly over the coaxial line (not shown) with which the pronged connector 18 is in electrical engagement. The presence of the horn reflector 46 acts to direct this emitted energy substantially axially of the assembly, and precludes any substantial radiation transverse to this longitudinal axis. Furthermore, due to the helically-wound nature of the conductor 42, the radiation which is emitted is circularly polarized, and the horn reflector 46 is effected to suppress side lobes in the radiation pattern. The horn reflector 46 also effectively isolates the antenna element 42 from its surrounding environment on the missile or other space vehicle, thus making it feasible to install the apparatus of FIG. 1 in virtually any desired location without bringing about a decrease in radiation efficiency.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim:

1. A device for coupling microwave energy between two separable portions of an airborne vehicle, said device further providing for the transmission of such energy through the atmosphere from the vehicle to a remote receiving point after the two portions of the vehicle have separated, said device comprising:

a first impedance-matching transformer integrally associated with one of the two vehicle portions and designed for connection to an energy-utilization means;

a second impedance-matching transformer integrally associated with the other of the two vehicle portions and designed for connection to an energy-generating source;

a coupling unit including a helically-wound conductor in permanent electrical engagement with said second transformer and in separable electrical engagement with said first transformer;

a frusto-conical reflector forming part of said coupling unit and coaxial with said helically-wound conductor, said reflector likewise being in permanent electrical engagement with said second transformer and in separable electrical engagement with said first transformer;

whereby, when the two portions of the airborne vehicle separate, said second transformer becomes disengaged from both said helically-wound conductor and from said reflector, so that said coupling unit becomes an antenna by means of which energy may be transmitted through the atmosphere from said vehicle to a remote receiving point.

2. A device for coupling microwave energy between two separable portions of an airborne vehicle, said device further providing for the transmission of such energy through the atmosphere from the vehicle to a remote receiving point after the two portions of the vehicle have separated, said device comprising:

a pair of electrical adaptors respectively associated with the two portions of the vehicle and integrally mounted thereon; and

a coupling unit integrally associated with one of said adaptors and separably associated with the remaining adaptor, said coupling unit having the dual function of transferring energy between the two vehicle portions prior to separation thereof and also acting to radiate energy into space following such separation.

3. A device according to claim 2 in which said coupling unit is in the form of a horn-helix antenna.

4. A device according to claim 2 in which said pair of adaptors comprise impedance-matching transformers each having an essentially cylindrical casing acting as an outer conductor and an inner conductor extending axially thereof;

and in which said coupling unit includes a helicallywound conductor the terminal portions of which are in electrical engagement with the respective inner conductors of said pair of transformers.

5. A device according to claim 4 in which said coupling unit includes a frusto-conical reflector positioned coaxially with said helically-wound conductor, said reflector being in electrical engagement with the cylindrical casing of each of said pair of transformers.

6. A device for selectively transferring RF energy from one section of a separable assembly to a further section thereof, said device further functioning to radiate such energy into space following separation of the assembly, said device including:

a pair of essentially coaxial transmission line terminations the impedances of which are selectively adjustable, one of said terminations being integrally associated with each section of the separable assembly;

a coupling device interposed between said line terminations and normally functioning to transfer energy therebetween when said assembly is in its unitary condition, said coupling device being integrally associated with one of said terminations and frangibly associated with the other of said terminations;

said coupling device also serving as an energy radiator following the frangible dissociation said coupling device from said other transmission line termination upon separation of the two sections of said assembly.

7. A device for coupling microwave energy between two separable portions of an airborne vehicle, said device further providing for the transmission of such energy through the atmosphere from the vehicle to a remote receiving point after the two portions of the vehicle have separated, said device comprising:

a first impedance-matching transformer integrally associated with one of the two vehicle portions and adapted to supply energy to a utilization means, said transformer being of an essentially coaxial nature and having a substantially cylindrical housing acting as an outer conductor, together with an axial inner conductor one end of which is provided with means for connecting a further conductor thereto;

a second-impedance matching transformer mounted coaxially with said first transformer and integrally associated with the other of the two vehicle portions and adapted to receive energy from a generating source contained within said other vehicle portions, said second transformer also being of an essentially coaxial nature and having a substantially cylindrical housing acting as an outer conductor together with an axial inner conductor one end of which is provided with means for connecting a further conductor thereto;

the cylindrical housings of both said first and second transformers being each provided with a radiallyextending flange, said flanges lying in spaced-apart parallel relationship and transverse to the axis of both said transformers;

a tubular support formed of insulating material, mounted coaxially with both said transformers, and interposed therebetween, said support having a flanged extension at one end thereof positioned to abut the flange of said second transformer;

a conductor helically wound on said support, one terminal portion of said helical conductor being securely connected to the inner conductor of said second transformer and separably connected to the inner conductor of said first transformer;

a frusto-conical reflector positioned coaxially with said tubular support and flaring outwardly from the vicinity of said second transformer to the vicinity of said first transformer, said reflector being formed with a transverse flange at its narrow end which is adapted to lie in face-to-face engagement with the flange of said second transformer and to secure therebetween the flanged extension of said tubular support;

an iris of generally annular configuration and designed to lie in face-to-face engagement with the radiallyextending flange formed on said first transformer, said iris having a radial dimension substantially identical to that of said flange and having an inwardly-extending recessed portion into which the flared portion of said reflector is separably receivable;

sair iris also having an axial aperture therein through which extends the helically-wound conductor, the latter then entering into separable electrical engagement with the inner conductor of said first transformer;

whereby, when the two portions of said airborne vehicle separate, the helically-wound conductor terminates its electrical engagement with the inner conductor of said first transformer and the conical reflector leaves the recessed portion of the iris, so that the helicallywound conductor, together with the said conical reflector, together form an antenna by means of which microwave energy may be directionally radiated through the atmosphere to a remote receiving point.

8. The combination of claim 7, in which each of said first and second transformers is provided with manuallyadjustable means for varying the transmission characteristics thereof so as to match the impedance of said utilization means to the impedance of said generating source.

References Cited by the Examiner UNITED STATES PATENTS 5/1956 Sichak. 2/1958 Martin et al. 343-906 

2. A DEVICE FOR COUPLING MICROWAVE ENERGY BETWEEN TWO SEPARABLE PORTIONS OF AN AIRBORNE VEHICLE, SAID DEVICE FURTHER PROVIDING FOR THE TRANSMISSION OF SUCH ENERGY THROUGH THE ATMOSPHERE FROM THE VEHICLE TO A REMOTE RECEIVING POINT AFTER THE TWO PORTIONS OF THE VEHICLE HAVE SEPARATED, SAID DEVICE COMPRISING: A PAIR OF ELECTRICAL ADAPTORS RESPECTIVELY ASSOCIATED WITH THE TWO PORTIONS OF THE VEHICLE AND INTEGRALLY MOUNTED THEREON; AND A COUPLING UNIT INTEGRALLY ASSOCIATED WITH ONE OF SAID ADAPTORS AND SEPARABLY ASSOCIATED WITH THE REMAINING ADAPTOR, SAID COUPLING UNIT HAVING THE DUAL FUNCTION OF TRANSFERRING ENERGY BETWEEN THE TWO VEHICLE PORTIONS PRIOR TO SEPARATION THEREOF AND ALSO ACTING TO RADIATE ENERGY INTO SPACE FOLLOWING SUCH SEPARATION. 